#include <FastLED.h>

// Define the number of LEDs and the data pin
#define NUM_LEDS 4
#define DATA_PIN 6  // Change this to the pin you're using for the WS2812B

CRGB leds[NUM_LEDS];

// Variables for the rainbow color cycling
uint8_t hue = 0;

void setup() {
  // Initialize the FastLED library
  FastLED.addLeds<WS2812B, DATA_PIN, GRB>(leds, NUM_LEDS);
  FastLED.setBrightness(100);  // Adjust brightness from 0 to 255
}

void loop() {
  // Cycle through all the colors of the rainbow
  for(int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CHSV(hue + (i * 10), 255, 255);  // Spread the hues across the LEDs
  }
  
  FastLED.show();  // Display the colors on the LEDs
  hue++;  // Increment the hue to move through the rainbow
  
  delay(50);  // Adjust speed of the color change
}